GEDI L1B Product Data Dictionary

Dimension Variable Description
MT Number of shots
AV Number of average waveform groups


Group: /
short_name (Attribute) GEDI_L1B ${DESCRIPTION}
Group: /METADATA/DatasetIdentification
abstract (Attribute) The GEDI L1A and L1B standard data product contains precise latitude, longitude, and height above the reference ellipsoid of the laser shot received bounce point for all laser shots. Geophysical corrections are applied to the surface return values for each laser shot. Geophysical corrections, atmospheric corrections, and the surface types are provided for each laser shot. ${DESCRIPTION}
characterSet (Attribute) utf8 ${DESCRIPTION}
creationDate (Attribute) File creation date
credit (Attribute) The software that generates the L1B product was designed and implemented within the GEDI Science Data Processing System at the NASA Goddard Space Flight Center in Greenbelt, Maryland. ${DESCRIPTION}
fileName (Attribute) Original file name
language (Attribute) eng ${DESCRIPTION}
originatorOrganizationName (Attribute) GSFC GEDI-SDPS > GEDI Science Data Processing System ${DESCRIPTION}
PGEVersion (Attribute) Product generating executive SDPS release ID
purpose (Attribute) The purpose of the L1B dataset is to provide geolocated waveforms and supporting datasets for each laser shot for all eight GEDI beams. This includes corrected and smoothed waveforms, geolocation parameters, and geophysical corrections. ${DESCRIPTION}
shortName (Attribute) GEDI_L1B ${DESCRIPTION}
spatialRepresentationType (Attribute) along-track ${DESCRIPTION}
status (Attribute) onGoing ${DESCRIPTION}
topicCategory (Attribute) geoscientificInformation ${DESCRIPTION}
uuid (Attribute) Universally unique identifier (UUID) for this file
VersionID (Attribute) SDPS DAAC release ID
Group: /BEAMXXXX
description (Attribute) "Coverage beam" or "Full power beam"
Label Datatype
(Dimensions)
long_name units
source
description
all_samples_sum UINT32
(MT)
All samples sum counts from the ADC (Analog-to-Digital Converter)
L0B
Sum of all values within the 10 km range window. delta_time
beam UINT16
(MT)
Beam counter
Derived
Beam number (0-11). 0, 11 delta_time
channel UINT8
(MT)
Channel counter
L0B
Channel number (0-7). 0, 7 delta_time
master_frac FLOAT64
(MT)
Master time fractional seconds seconds
Derived
Master time, fractional part. master_int+master_frac is equivalent to /BEAMXXXX/geolocation/delta_time and /BEAMXXXX/geophys_corr/delta_time.
master_int UINT32
(MT)
Master time integer seconds seconds
Derived
Master time, integer part. Seconds since master_time_epoch. master_int+master_frac is equivalent to /BEAMXXXX/geolocation/delta_time and /BEAMXXXX/geophys_corr/delta_time.
noise_mean_corrected FLOAT64
(MT)
Noise mean counts from the ADC (Analog-to-Digital Converter)
L0B
Noise mean. delta_time
noise_stddev_corrected FLOAT64
(MT)
Standard deviation counts from the ADC
Derived
Corrected noise standard deviation. delta_time
nsemean_even FLOAT32
(MT)
Noise mean even counts from the ADC
Instrument housekeeping
Noise mean of the beam's detector channel from even sub-converter. delta_time
nsemean_odd FLOAT32
(MT)
Noise mean odd counts from the ADC
Instrument housekeeping
Noise mean of the beam's odd sub-converter. delta_time
rx_energy FLOAT64
(MT)
RX energy sample number (~1ns) multiplied by counts from the ADC
Derived
Integrated energy in RX waveform after subtracting the noise mean. delta_time
rx_offset UINT16
(MT)
RX offset sample intervals (~1 ns)
L0B
Time interval from first stored sample to first downloaded RX sample (1ns resolution). delta_time
rx_open UINT32
(MT)
RX open sample intervals (~1 ns)
L0B
Time interval from t0 to first stored RX sample (4ns resolution). delta_time
rx_sample_count UINT16
(MT)
RX sample count sample intervals
L0B
The number of sample intervals (elements) in each RX waveform. delta_time
rx_sample_start_index UINT64
(MT)
RX sample start index index (origin 1)
Derived
The index in the rxwaveform dataset of the first element of each RX waveform. The indices start at 1. delta_time
rxwaveform FLOAT32
(UNLIMITED)
RX waveform counts from the ADC
Derived
The corrected receive (RX) waveforms. Use rx_sample_count and rx_sample_start_index to identify the location of each waveform.
selection_stretchers_x UINT16
(MT)
Selection stretchers X sample intervals (~1 ns)
L0B
Commanded number of samples added to algo section on the left. delta_time
selection_stretchers_y UINT16
(MT)
Selection stretchers Y sample intervals (~1 ns)
L0B
Commanded number of samples added to algo section on the right. delta_time
shot_number UINT64
(MT)
Shot number counter
Derived
Unique shot ID. delta_time
stale_return_flag UINT8
(MT)
Stale return flag boolean
L0B
Indicates that a "stale" cue point from the coarse search algorithm is being used. 0, 1 delta_time
th_left_used UINT16
(MT)
Threshold fine left used counts from the ADC
L0B
Count values for left threshold used in fine search. Two consecutive points at or above this value indicates pulse detection. delta_time
tx_egamplitude FLOAT32
(MT)
TX extended Gaussian amplitude counts from the ADC
Derived
Amplitude of the extended Gaussian fit to the TX waveform. delta_time
tx_egamplitude_error FLOAT32
(MT)
TX extended Gaussian amplitude error counts from the ADC
Derived
Error on tx_egamplitude. delta_time
tx_egbias FLOAT32
(MT)
TX extended Gaussian bias counts from the ADC
Derived
Bias of the extended Gaussian fit to the TX waveform. delta_time
tx_egbias_error FLOAT32
(MT)
TX extended Gaussian bias error counts from the ADC
Derived
Error on tx_egbias. delta_time
tx_egflag UINT8
(MT)
TX extended Gaussian flag flag
Derived
Extended Gaussian fit status flag. 1=convergence in chi2 value, 2=convergence in parameter value, 3=convergence in chi2 and parameter values, 4=convergence in orthogonality, 5=maximum number of iterations reached, 6=ftol too small (no further improvement), 7=xtol too small (no further improvement), 8=gtol too small (no further improvement). delta_time
tx_eggamma FLOAT32
(MT)
TX extended Gaussian gamma N/A
Derived
Gamma value of the extended Gaussian fit to the TX waveform. delta_time
tx_eggamma_error FLOAT32
(MT)
TX extended Gaussian gamma error N/A
Derived
Error on tx_eggamma. delta_time
tx_egsigma FLOAT32
(MT)
TX extended Gaussian sigma sample intervals (~1 ns)
Derived
Sigma of the extended Gaussian fit to the TX waveform. delta_time
tx_egsigma_error FLOAT32
(MT)
TX extended Gaussian sigma error sample intervals (~1 ns)
Derived
Error on tx_egsigma. delta_time
tx_gloc FLOAT32
(MT)
TX Gaussian location sample intervals (~1 ns)
Derived
Location (mean) of the Gaussian fit to the TX waveform. delta_time
tx_gloc_error FLOAT32
(MT)
TX Gaussian location error sample intervals (~1 ns)
Derived
Error on tx_gloc. delta_time
tx_pulseflag UINT8
(MT)
TX pulse flag boolean
Derived
Set to 1 if a pulse is detected in the TX waveform. 0, 1 delta_time
tx_sample_count UINT16
(MT)
TX sample count sample intervals
Derived
The number of sample intervals (elements) in each TX waveform. 0, 1 delta_time
tx_sample_start_index UINT64
(MT)
TX sample start index index (origin 1)
Derived
The index in the rxwaveform dataset of the first element of each RX waveform. The indices start at 1. 0, 1 delta_time
txwaveform FLOAT32
(UNLIMITED)
TX waveform counts from the ADC
Derived
The corrected transmit (TX) waveforms. Use tx_sample_count and tx_sample_start_index to identify the location of each waveform.
Group: /BEAMXXXX/ancillary
Label Datatype
(Dimensions)
long_name units
source
description
master_time_epoch FLOAT64
(1)
Master time epoch seconds
Number of GPS seconds between the GPS epoch (1980-01-06T00:00:00Z) and the GEDI epoch (2018-01-01T00:00:00Z). Add this value to delta_time parameters to compute full GPS seconds (relative to the GPS epoch) for each data point.
mean_samples INT64
(1)
Mean samples shots
Configuration
Averaging window (shots) for non-repeated odd-even measurements from housekeeping.
smoothing_width FLOAT64
(1)
Smoothing width sample intervals (~1 ns)
Configuration
The 1-sigma width (nsec) of the gaussian kernel used to smooth the corrected waveform.
Group: /BEAMXXXX/geolocation
description (Attribute) Geolocation ${DESCRIPTION}
Label Datatype
(Dimensions)
long_name units
source
description
altitude_instrument FLOAT64
(MT)
Instrument altitude meters
Derived
Height of the instrument diffractive optical element (DOE) above the WGS84 ellipsoid. delta_time latitude_instrument longitude_instrument delta_time
altitude_instrument_error FLOAT32
(MT)
Instrument altitude error meters
Derived
Error on altitude_instrument. delta_time latitude_instrument longitude_instrument delta_time
bounce_time_offset_bin0 FLOAT64
(MT)
Bounce time offset bin 0 seconds
Derived
The difference between the transmit time and the time at the start of the RX window delta_time latitude_bin0 longitude_bin0 delta_time
bounce_time_offset_bin0_error FLOAT32
(MT)
Bounce time offset bin 0 error seconds
Derived
Error on bounce_time_offset_bin0. delta_time latitude_bin0 longitude_bin0 delta_time
bounce_time_offset_lastbin FLOAT64
(MT)
Bounce time offset last bin seconds
Derived
The difference between the transmit time and the time at the end of the RX window delta_time latitude_lastbin longitude_lastbin delta_time
bounce_time_offset_lastbin_error FLOAT32
(MT)
Bounce time offset last bin error seconds
Derived
Error on bounce_time_offset_lastbin. delta_time latitude_lastbin longitude_lastbin delta_time
degrade INT8
(MT)
Degrade flag
Derived
Non-zero values indicate the shot occured during a degraded period. A non-zero tens digit indicates degraded attitude, a non-zero ones digit indicates a degraded trajectory. 3X=ADF CHU solution unavailable (ST-2); 4X=Platform attitude; 5X=Poor solution (filter covariance large); 6X=Data outage (platform attitude gap also); 7X=ST 1+2 unavailable (similar boresight FOV); 8X=ST 1+2+3 unavailable; 9X=ST 1+2+3 and ISS unavailable; X1=Maneuver; X2=GPS data gap; X3=ST blinding; X4=Other; X5=GPS receiver clock drift; X6=X5+X1; X7=X5+X2; X8=X5+X3; X9=X5+X4. 0, 99 delta_time
delta_time FLOAT64
(MT)
Delta time seconds since 2018-01-01
Derived
Transmit time of the shot, measured in seconds from the master_time_epoch. By adding the offset contained within /BEAMXXXX/ancillary/master_time_epoch to delta_time, the time in GPS seconds relative to the GPS epoch can be computed. Equivalent to /BEAMXXXX/master_int+/BEAMXXXX/master_frac. delta_time latitude_bin0 longitude_bin0
digital_elevation_model FLOAT32
(MT)
Digital elevation model meters
TanDEM-X DEM
Digital elevation model height above the WGS84 ellipsoid. Interpolated at latitude_bin0 and longitude_bin0 from the TandemX 90m product. -962, 10038 delta_time latitude_bin0 longitude_bin0 delta_time -999999.0
digital_elevation_model_srtm FLOAT32
(MT)
Digital elevation model SRTM meters
SRTM DEM
Digital elevation model height above the WGS84 ellipsoid. Evaluated at rx_sample_count-selection_stretcher_y from the SRTM 30m product. -962, 10038 delta_time latitude_bin0 longitude_bin0 delta_time -999999.0
elevation_bin0 FLOAT64
(MT)
Bounce elevation bin 0 meters
Derived
Height of the start of the RX window, relative to the WGS-84 ellipsoid. Includes corrections due to the range bias, atmospheric path delay, solid Earth tides, ocean loading, ocean pole tide, and solid Earth pole tide. delta_time latitude_bin0 longitude_bin0 delta_time
elevation_bin0_error FLOAT32
(MT)
Bounce elevation bin 0 error meters
Derived
Error on elevation_bin0. delta_time latitude_bin0 longitude_bin0 delta_time
elevation_lastbin FLOAT64
(MT)
Bounce elevation last bin meters
Derived
Height of the end of the RX window, relative to the WGS-84 ellipsoid. Includes corrections due to the range bias, atmospheric path delay, solid Earth tides, ocean loading, ocean pole tide, and solid Earth pole tide. delta_time latitude_lastbin longitude_lastbin delta_time
elevation_lastbin_error FLOAT32
(MT)
Bounce elevation last bin error meters
Derived
Error on elevation_lastbin. delta_time latitude_lastbin longitude_lastbin delta_time
latitude_bin0 FLOAT64
(MT)
Bounce latitude bin 0 degrees
Derived
Latitude of the start of the RX window. -90, 90 delta_time longitude_bin0 delta_time
latitude_bin0_error FLOAT32
(MT)
Bounce latitude bin 0 error degrees
Derived
Error on latitude_bin0. delta_time latitude_bin0 longitude_bin0 delta_time
latitude_lastbin FLOAT64
(MT)
Bounce latitude last bin degrees
Derived
Latitude of the end of the RX window. -90, 90 delta_time longitude_lastbin delta_time
latitude_lastbin_error FLOAT32
(MT)
Bounce latitude last bin error degrees
Derived
Error on latitude_lastbin. delta_time latitude_lastbin longitude_lastbin delta_time
latitude_instrument FLOAT64
(MT)
Instrument latitude degrees
Derived
Latitude of the instrument diffractive optical element (DOE) at laser transmit time. -90, 90 delta_time
latitude_instrument_error FLOAT32
(MT)
Instrument latitude error degrees
Derived
Error on latitude_instrument. delta_time
local_beam_azimuth FLOAT32
(MT)
Local beam azimuth radians
Derived
Azimuth of the unit pointing vector for the laser in the local ENU frame. The angle is measured from North and positive towards East. -180, 180 delta_time latitude_bin0 longitude_bin0 delta_time
local_beam_azimuth_error FLOAT32
(MT)
Local beam azimuth error radians
Derived
Error on local_beam_azimuth. delta_time latitude_bin0 longitude_bin0 delta_time
local_beam_elevation FLOAT32
(MT)
Local beam elevation radians
Derived
Elevation of the unit pointing vector for the laser in the local ENU frame. The angle is measured from East-North plane and positive towards Up. 1.39626340159546, 1.57079632679490 delta_time latitude_bin0 longitude_bin0 delta_time
local_beam_elevation_error FLOAT32
(MT)
Local beam elevation error radians
Derived
Error on local_beam_elevation. delta_time latitude_bin0 longitude_bin0 delta_time
longitude_bin0 FLOAT64
(MT)
Bounce longitude bin 0 degrees
Derived
Longitude of the start of the RX window. -180, 180 delta_time latitude_bin0 delta_time
longitude_bin0_error FLOAT32
(MT)
Bounce longitude bin 0 error degrees
Derived
Error on longitude_bin0. delta_time latitude_bin0 longitude_bin0 delta_time
longitude_lastbin FLOAT64
(MT)
Bounce longitude last bin degrees
Derived
Longitude of the end of the RX window. -180, 180 delta_time latitude_lastbin delta_time
longitude_lastbin_error FLOAT32
(MT)
Bounce longitude last bin error degrees
Derived
Error on longitude_lastbin. delta_time latitude_lastbin longitude_lastbin delta_time
longitude_instrument FLOAT64
(MT)
Instrument longitude degrees
Derived
Longitude of the instrument diffractive optical element (DOE) at laser transmit time. -180, 180 delta_time
longitude_instrument_error FLOAT32
(MT)
Instrument longitude error degrees
Derived
Error on longitude_instrument. delta_time
mean_sea_surface FLOAT32
(MT)
Mean sea surface meters
DTU15
Mean sea surface height above the WGS84 ellipsoid, includes the geoid. Interpolated at latitude_bin0 and longitude_bin0 from DTU15. delta_time latitude_bin0 longitude_bin0 delta_time
neutat_delay_derivative_bin0 FLOAT32
(MT)
(Neutral atmosphere delay)/dh bin 0 meters/meter
Derived
Change in neutral atmospheric delay per height change for the start of the RX window. delta_time latitude_bin0 longitude_bin0 delta_time
neutat_delay_derivative_lastbin FLOAT32
(MT)
(Neutral atmosphere delay)/dh last bin meters/meter
Derived
Change in neutral atmospheric delay per height change for the end of the RX window. delta_time latitude_lastbin longitude_lastbin delta_time
neutat_delay_total_bin0 FLOAT32
(MT)
Total neutral atmospheric delay bin 0 meters
Derived
Total neutral atmosphere delay correction (wet+dry) from the TX pulse to the start of the RX window (computed according to ICESat-2 ATL03A ATDB). This value is subtracted from the range during geolocation. delta_time latitude_bin0 longitude_bin0 delta_time
neutat_delay_total_lastbin FLOAT32
(MT)
Total neutral atmospheric delay last bin meters
Derived
Total neutral atmosphere delay correction (wet+dry) from the TX pulse to the end of the RX window (computed according to ICESat-2 ATL03A ATDB). This value is subtracted from the range during geolocation. delta_time latitude_lastbin longitude_lastbin delta_time
range_bias_correction FLOAT32
(MT)
Range bias correction meters
Derived
The range bias applied to the range measurement. This value is subtracted from the range to get the corrected range. delta_time latitude_bin0 longitude_bin0 delta_time
shot_number UINT64
(MT)
Shot number counter
Derived
Unique shot ID. delta_time latitude_bin0 longitude_bin0 delta_time
solar_azimuth FLOAT32
(MT)
Solar azimuth degrees
Derived
The azimuth of the sun position vector from the laser bounce point position in the local ENU frame. The angle is measured from North and is positive towards East. -180, 180 delta_time latitude_bin0 longitude_bin0 delta_time
solar_elevation FLOAT32
(MT)
Solar elevation degrees
Derived
The elevation of the sun position vector from the laser bounce point position in the local ENU frame. The angle is measured from the East-North plane and is positive Up. -90, 90 delta_time latitude_bin0 longitude_bin0 delta_time
surface_type INT8
(5,MT)
Surface type boolean
ICESat-2 surface type mask
Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water. 0, 1 delta_time latitude_bin0 longitude_bin0 delta_time
Group: /BEAMXXXX/geophys_corr
description (Attribute) Geophysical corrections ${DESCRIPTION}
Label Datatype
(Dimensions)
long_name units
source
description
delta_time FLOAT64
(MT)
Delta time seconds since 2018-01-01
Derived
Transmit time of the shot, measured in seconds from the master_time_epoch. By adding the offset contained within /BEAMXXXX/ancillary/master_time_epoch to delta_time, the time in GPS seconds relative to the GPS epoch can be computed. Equivalent to /BEAMXXXX/master_int+/BEAMXXXX/master_frac.
dynamic_atmosphere_correction FLOAT32
(MT)
Dynamic atmosphere correction meters
MOG2D
Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. delta_time
geoid FLOAT32
(MT)
Geoid meters
Derived from EGM2008
Geoid height above WGS-84 reference ellipsoid (range -107 to 86m). Not applied on the product. delta_time
tide_earth FLOAT32
(MT)
Earth tide meters
IERS conventions (2010)
Solid Earth tides delta_time
tide_load FLOAT32
(MT)
Load tide meters
GOT 4.8
Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). delta_time
tide_ocean FLOAT32
(MT)
Ocean tide meters
GOT 4.8
Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium). delta_time
tide_ocean_pole FLOAT32
(MT)
Ocean pole tide meters
IERS conventions (2010)
Oceanic surface rotational deformation due to polar motion (-2 to 2 mm). delta_time
tide_pole FLOAT32
(MT)
Solid earth pole tide meters
IERS conventions (2010)
Solid Earth Pole Tide -- Rotational deformation due to polar motion (-1.5 to 1.5 cm). delta_time